Universe.Physics.BulletSPlugin.BSDynamics.ComputeLinearHover C# (CSharp) Method

        public void ComputeLinearHover(float pTimestep)
        {
            // m_VhoverEfficiency: 0=bouncy, 1=totally damped
            // m_VhoverTimescale: time to achieve height
            if ((m_flags & (VehicleFlag.HOVER_WATER_ONLY | VehicleFlag.HOVER_TERRAIN_ONLY | VehicleFlag.HOVER_GLOBAL_HEIGHT)) != 0 && (m_VhoverHeight > 0) && (m_VhoverTimescale < 300))
            {
                // We should hover, get the target height
                if ((m_flags & VehicleFlag.HOVER_WATER_ONLY) != 0)
                {
                    m_VhoverTargetHeight = GetWaterLevel(VehiclePosition) + m_VhoverHeight;
                }
                if ((m_flags & VehicleFlag.HOVER_TERRAIN_ONLY) != 0)
                {
                    m_VhoverTargetHeight = GetTerrainHeight(VehiclePosition) + m_VhoverHeight;
                }
                if ((m_flags & VehicleFlag.HOVER_GLOBAL_HEIGHT) != 0)
                {
                    m_VhoverTargetHeight = m_VhoverHeight;
                }

                if ((m_flags & VehicleFlag.HOVER_UP_ONLY) != 0)
                {
                    // If body is already heigher, use its height as target height
                    if (VehiclePosition.Z > m_VhoverTargetHeight)
                    {
                        m_VhoverTargetHeight = VehiclePosition.Z;

                        // A 'misfeature' of this flag is that if the vehicle is above it's hover height,
                        //     the vehicle's buoyancy goes away. This is an SL bug that got used by so many
                        //    scripts that it could not be changed.
                        // So, if above the height, reapply gravity if buoyancy had it turned off.
                        if (m_VehicleBuoyancy != 0)
                        {
                            Vector3 appliedGravity = ControllingPrim.ComputeGravity(ControllingPrim.Buoyancy) * m_vehicleMass;
                            VehicleAddForce(appliedGravity);
                        }
                    }
                }

                if ((m_flags & VehicleFlag.LOCK_HOVER_HEIGHT) != 0)
                {
                    if (Math.Abs(VehiclePosition.Z - m_VhoverTargetHeight) > 0.2f)
                    {
                        Vector3 pos = VehiclePosition;
                        pos.Z = m_VhoverTargetHeight;
                        VehiclePosition = pos;

                        VDetailLog("{0},  MoveLinear,hover,pos={1},lockHoverHeight", ControllingPrim.LocalID, pos);
                    }
                }
                else
                {
                    // Error is positive if below the target and negative if above.
                    Vector3 hpos = VehiclePosition;
                    float verticalError = m_VhoverTargetHeight - hpos.Z;
                    float verticalCorrection = verticalError / m_VhoverTimescale;
                    verticalCorrection *= m_VhoverEfficiency;

                    hpos.Z += verticalCorrection;
                    VehiclePosition = hpos;

                    // Since we are hovering, we need to do the opposite of falling -- get rid of world Z
                    Vector3 vel = VehicleVelocity;
                    vel.Z = 0f;
                    VehicleVelocity = vel;

                    /*
                    float verticalCorrectionVelocity = verticalError / m_VhoverTimescale;
                    Vector3 verticalCorrection = new Vector3(0f, 0f, verticalCorrectionVelocity);
                    verticalCorrection *= m_vehicleMass;

                    // TODO: implement m_VhoverEfficiency correctly
                    VehicleAddForceImpulse(verticalCorrection);
                     */

                    VDetailLog(
                        "{0},  MoveLinear,hover,pos={1},eff={2},hoverTS={3},height={4},target={5},err={6},corr={7}",
                        ControllingPrim.LocalID, VehiclePosition, m_VhoverEfficiency,
                        m_VhoverTimescale, m_VhoverHeight, m_VhoverTargetHeight,
                        verticalError, verticalCorrection);
                }
            }
        }